As the United States heads into the final stages of its presidential election, a return to the White House by Donald Trump could have profound and destabilising consequences for the Western Balkans, according to a new paper from the European Council on Foreign Relations (ECFR). 

The report warns specifically that a new Trump administration would likely shift from a neutral stance towards the region to actively promoting Serb interests. 

This could undermine the fragile stability in Bosnia & Herzegovina, reignite calls for a contentious Serbia-Kosovo land swap and embolden actors with secessionist aims.

“The most immediate risk is that the US would go from seeking to balance power in the Western Balkans (however imperfectly) under Biden to actively preferring Serb interests,” said the report’s authors, Adnan Ćerimagić, a senior analyst for the Western Balkans at the European Stability Initiative (ESI) think-tank, and Majda Ruge, senior policy fellow with the Wider Europe programme at the ECFR. 

The report’s authors point out that during his first term, Trump’s administration took an unusually hands-on approach to the Balkans. 

This was spearheaded by his envoy, Richard Grenell, who sought a deal between Serbia and Kosovo but achieved limited results. According to the ECFR, Trump’s re-election could see Grenell return to the role, potentially “concentrating on the region right away in his second term”. 

Since Trump’s election defeat in 2020, Grenell has maintained close ties with Serbian President Aleksandar Vucic, a relationship that ECFR argues could deepen under another Trump presidency. As Vucic himself hinted, Serbia is “waiting for a different political opportunity”, suggesting a potential alignment with a less interventionist US.

Under Biden, the US has ostensibly acted as a balancing force, supporting regional stability, though often with criticisms of being too lenient toward Vucic. A Trump administration, however, might shift toward openly favouring Serbia, heightening tensions across the region. 

“Trump does not tend to see the region as a US strategic interest,” the ECFR notes, leaving the region’s stability potentially hostage to unpredictable policy shifts.

An expected consequence of such a shift would be a breakdown in efforts to manage the ongoing friction between Serbia and Kosovo. The prospect of a land swap – a plan for Serbia to gain sovereignty over ethnic Serb municipalities in northern Kosovo, abandoned in Trump’s first term due to German opposition – could resurface with Grenell at the helm. 

Ćerimagić and Ruge warn that this policy could “force Pristina to comply,” undermining Kosovo’s sovereignty and sparking unrest in a sensitive border region. The paper suggests that Serbia might respond by “freezing” negotiations with Kosovo and pressing for greater control over these areas under the guise of a land swap agreement, a policy that Trump’s administration could potentially endorse.

Hungary’s Prime Minister Viktor Orbán, already an important figure in the region, could also gain renewed influence over Western Balkans policy should Trump return to office, according to the ECFR paper. 

Orbán, a key Trump ally and a vocal supporter of nationalist forces in the Balkans, has consistently backed separatist leaders like Milorad Dodik, president of Bosnia’s Serb entity, Republika Srpska. Under Trump, the paper contends, Orbán’s sway could grow within European Union policy circles, strengthening his ability to shield allies like Dodik from EU sanctions and further pushing Bosnia towards dysfunction.

The report further highlights how Trump’s return could remove the deterrent effect of US sanctions on actors like Dodik, who has signalled his ambition to withdraw Republika Srpska from central institutions. A rollback of sanctions, the paper argues, would create “a legal, economic, and logistical bonfire” for Bosnia, leaving its institutions fractured and borders vulnerable.

The paper also issues a stark warning to the EU, which has often deferred to US policy in the region. Should Washington disengage or adopt a less neutral role, the report urges EU member states to prepare for a proactive stance on the Western Balkans, recommending a package of deterrence measures independent of US support. The report argues this would allow Europe to act decisively, especially given Hungary’s track record of supporting Serbian expansionist aims, which, under a Trump-aligned US, would weaken the EU’s policy influence in the Balkans.

Under Biden, Ćerimagić and Ruge point out, the US has prevented several worst-case scenarios in the region. Although American policy has been criticised as lenient on Vucic’s administration, it has helped keep Serbia’s nationalist agenda in check and avoided a potential breakdown in Bosnia’s governance, they argued. A second Trump presidency, by contrast, would leave Europe’s leaders to take on this stabilising role.